Maybe we should all share what products past their exp date taste noticeably bad. Those nutritious shakes like Ensure taste just awful at their exp date, the vitamin and supplements start to overwhelm the milkshake flavor, yuck. Canned foods do ok if what's inside the can is flavorful to begin with, such as canned chili. However, canned foods containing simple tasting foods (not packed with flavor) will start tasting like the can soon after the exp. date. Some foods like cereal that are packaged in plastic will soon start absorbing the smell of plastic packaging after the exp date.

Heavy cream doesn't, but sine I don't know what heavy cream looks or smells like if it is bad, I usually don't keep it past the exp date. And by exp date I mean a week after I notice it has passed the date.

You can always use sour dairy items for baking. Sour milk isn't a health risk, just lousy tasting. But in a coffee cake or scones? You can't tell the milk was sour. We've never not liked something I've baked with spoiled milk. After all, when I was a kid if we didn't have my Nana would add a bit of vinegar or lemon juice to MAKE it sour! Haven't tried it for things like pancakes or waffles though.

When I was young, there was always a jar of clabber in the icebox. Clabber and lard makes the best biscuits in the world. 'Course, these days milk don't go bad the same way as it did in the 50's and early 60's. I ain't quite sure what the difference is but it just ain't the same.

__________________I used to be a racist, but I don't have much interest in it since Dale Earnhardt got killed.
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
Good judgement comes from experience; experience comes from bad judgement.

Actually, on further thought, "go bad" is not what I should have said. "Turn" would be a better term.

__________________I used to be a racist, but I don't have much interest in it since Dale Earnhardt got killed.
Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
Good judgement comes from experience; experience comes from bad judgement.

When I was young, there was always a jar of clabber in the icebox. Clabber and lard makes the best biscuits in the world. 'Course, these days milk don't go bad the same way as it did in the 50's and early 60's. I ain't quite sure what the difference is but it just ain't the same.

I have noticed that too. Milk doesn't get sour; it goes bad.

When I make sour milk for making quark, I have to inoculate it with sour cream or left over clabbered milk from the last batch.

I think they pasteurize it to a higher temperature that kills off all the nice micro-organisms.

__________________
May you live as long as you wish and love as long as you live.
Robert A. Heinlein

When I was young, there was always a jar of clabber in the icebox. Clabber and lard makes the best biscuits in the world. 'Course, these days milk don't go bad the same way as it did in the 50's and early 60's. I ain't quite sure what the difference is but it just ain't the same.

It's because milk nowadays is almost all pasteurised, sterilised or UHT, whereas back then there was more "raw" milk available. (An old lady of my childhood acquaintance always referred to pasteurised milk as "boiled germs")

I use unflavoured and unsweetened yoghourt in scones and similar things, where you would probably use buttermilk. I make my own yoghourt so always have it on hand. I don't think I'd risk using sour/bad milk these days